The main purpose of this study is to investigate the effect of retatrutide on renal function in participants with overweight or obesity and chronic kidney disease (CKD), with or without Type 2 Diabetes (T2D). The study will last around 31 weeks.

Inclusion Criteria:

• Have a body mass index (BMI) ≥27 kilogram/square meter (kg/m²)

• Have either

  • no T2D with an HbA1c < 6.5% or
  • have T2D with an HbA1c ≤ 9.5% and treated with diet and exercise only or with stable doses of up to 3 oral antihyperglycemic medications, with or without basal insulin for at least 90 days before screening.

• Have been diagnosed with chronic kidney disease (CKD).

Exclusion Criteria:

• Have a self-reported change in body weight >5 kilogram (kg) (11 pounds) within 90 days before screening.
• Have used in 90 days before the screening any of the following antihyperglycemic class: Dipeptidyl Peptidase IV (DPP4) inhibitors, amylin analogs, glucagon-like peptide-RA (GLP-RA), gastric inhibitory polypeptide (GIP)/GIP-1 RA, and short acting or rapid acting insulins or U500 Insulin
• Have a prior or planned surgical treatment for obesity
• Have Type 1 Diabetes (T1D)
• Have acute or chronic hepatitis
• Have a history of malignant disease within 5 years before screening.

Anonymized individual patient level data will be provided in a secure access environment upon approval of a research proposal and a signed data sharing agreement.

Data are available 6 months after the primary publication and approval of the indication studied in the US and European Union (EU), whichever is later. Data will be indefinitely available for requesting.

A research proposal must be approved by an independent review panel and researchers must sign a data sharing agreement.

Phase 2b